The January transfer window is open for business with Premier League clubs set for a busy few weeks of wheeling and dealing.

To celebrate one of the most bonkers months of the footballing year, we have rounded up some of the most outrageous facts surrounding the winter window.

What is the most money ever spent in a single January transfer window?

Prior to last season, the 2018 January window had topped the spending charts with an estimated £430million spent across England's top tier.

However, that total was blown out of the water in 2023 when a staggering £815m was splashed out — accounting for 79% of the total spend for Europe's top five leagues in that window.

Staggeringly, over a third of that £815m was spent by Chelsea alone.

What are the most expensive Premier League January transfer window signings?

Unsurprisingly, Chelsea also take the title for the most expensive January acquisition having broken the British transfer record to sign Enzo Fernandez on deadline day in 2023.

The Argentinian World Cup winner, 22, joined the Blues from Benfica for an eye-watering £106.5m — trumping the previous record of £88.5m they set themselves just two weeks previous when signing Shakhtar Donetsk winger Mykhailo Mudryk.

Trailing those pair in third place is Liverpool's £75m pick-up of Virgil van Dijk, followed by Manchester City's £57m deal to bring Aymeric Laporte to the Etihad.

Arsenal's record January fee was £56m to land Pierre-Emerick Aubameyang, while Manchester United splashed out an initial £47m on Portuguese midfielder Bruno Fernandes.

Which teams have signed the most players in a single January transfer window?

There are no prizes for guessing the winners of this one, either.

Chelsea's 2023 winter window was not only record-breaking in monetary terms but also in volume, with no less than eight new faces arriving in West London last January.

Marquee additions Fernandez and Mudryk were joined by Benoit Badiashile, Noni Madueke, Joao Felix, Andrey Santos, Malo Gusto and David Datro Fofana.

Which January transfer window players have been the biggest flops?

Though it is hard to quantify the biggest flops, plenty of high-profile January signings have certainly failed to live up to their billing over the last 20 years.

Andy Carroll's deadline day move from Newcastle to Liverpool was an unmitigated disaster, with the towering striker managing just six Premier League goals for the Reds during his time at Anfield.

Alexis Sanchez was outstanding for Arsenal but his shock January switch to Manchester United ended up being a nightmare — the Chilean netting just five times in 45 games for the Red Devils. 

And just to ensure Chelsea get their standard mention, it is only fair to reference their £50m swoop for Fernando Torres in 2011.

The Spaniard did not hit his previous heights in West London, though FA Cup, Champions League and Europa League medals represent a more than respectable haul.